High pressure reinforced hydraulic hose is typically used on a variety of fluid power operated machines, such as earth-moving machines, to provide a flexible connection between several moving parts of a hydraulic circuit employed on or within the machine. Such hoses may include a hollow polymeric inner tube on which successive cylindrical layers of reinforcing material, such as wire or textile, are concentrically applied to contain the radial and axial pressures developed within the inner tube.
Such hydraulic hoses can be used to connect between various control valves in a hydraulic system. These control valves are often dispersed throughout the overall hydraulic system, for example of the fluid power operated machine, or other types of applications. Control valves are electronically actuated to control their opening/closing operations, typically from a control panel associated with the hydraulic system. Wiring is therefore routed throughout the hydraulic system of a machine to control valve actuations. This can include to very remote portions of a machine, such as at the end of a boom where a hydraulic control valve may be placed.
In connection with use of hydraulic hoses, increasingly applications are demanding hose constructions with both high burst strength and long term fatigue resistance. Using conventional technology, the burst strength of a hose design may be increased by adding additional reinforcing material and/or layers, a practice which is generally discouraged because of its negative impact on the flexibility of the hose, or by universally increasing the tensile strength of each layer of reinforcement material, which may come at the expense of hose fatigue resistance.
In some circumstances, it is desirable to detect, in a non-destructive and non-disruptive manner a likelihood of failure of a hydraulic hose. One solution providing this capability is discussed in U.S. Pat. No. 7,555,936, and discloses connecting a monitor circuit between two parallel, at least partially-conductive layers of a hose wall. A change in an electrical property observed by that monitor circuit may indicate a change in a property of the hose wall structure that might indicate impending failure of the hose wall.
The focus of using such hydraulic hoses has been related to detection of failures of the hose itself. However, other problems exist in overall hydraulic systems that may use such hoses. For example, the routing of control lines to each control valve provides additional complexity and cost to an overall system design, as well as extra assembly time and a potential for the wire to be damaged during use.
For these and other reasons, improvements are desirable.